Method of constructing radiator fins



July 14, 1936. H. J. KRAcKowlzER 2,047,207

BUI f4 (I tttt neg 'Patented July 14, 1936 'Y UNITED ASTATI-:s

PA'IEN'r OFFICE METHOD OF lcous'rnuo'trmcr RADIATOR -FiNs Hermann J. Krackowizer, Chicago, IIL, assigner to Oscar Wol, Chicago, Ill.

Original application May l0, 1933, Serial No.

670,338, now Patent No. 1,983,549, dated December 11, 1934. Divided and this application October 15, 1934, Serial No. 748,376

3 Claims. (Cl. 113-118) This invention relates to a method -of making radiators, and particularly to radiators having plate ns to increase the radiating surfaces of iubes in which ows the uid to be heated or coo ed.

The object of thevinvention is to provide an improvement in the method of constructing plate ns which have spacer lugs formed integrally with the4 fins and punched therefrom on three sides, leavingfonel Aside uncut, and the lugs being bent at right angles to the nn to space the plate ilns apart when assembled upon tubes. These lugs, as heretofore-constructed' as shown for example in the l tothe part of the nn plate from which it radiates.

causing choking of the h eat' from the plate to the lug. After assembling the plate dns on the tubes, it being heretofore thepractice to expand the tube outward to make a tight it, the lugs had a tendency to bend out of shape because they were structurally weak or narrowest at the point of 'maximum' strain.

In-these heretofore constructed lugs and plates, the lugs straddled the holes and when hot dipping or electroplating with metal in the heretofore constructed trapezoidal ,lugs which straddle a hole, the coating metal doesvnot joina lug and an adjacent plate except in two small spots which was a disadvantage and ordinarily the heretofore constructed lugged fin plate did not extend from one row of tubes to the'next and this necessitated la gap between the plates on each tube which further resulted in cutting down the radiating area by the sides of this gap. This gap was found to be disadvantageous for several reasons. For exampie, condensation accumulated in the gaps instead.

of running off and when 'the condensation gath- -ered in the gapsit frequently turned to ice which gradually spread over the radiating surfaces and formed in such thick masses as to greatly reduce Athe circulation of air so vital in air cooled radlon only 'one tube the .plate tended to rotate on the tube when hot dipped and this gave the finished radiator a poor appearance.

To overcome the difficulties heretofore encountered in radiators of this character, applicant vhas extended his plate over a plurality of tubes 5 and cuts 'andpunches his lugs from the plate and also openings for the tubes as will now be more fully described in connection with the at-l tached drawing in whichif Figure 1 represents a plate with the lugs cut 10 and punched therefrom.

Figure 2 shows the plates put on a plurality o1' tubes.

Figure 3 shows the position of the cut out lugs when the plate is turned at 180 from the position 15 'shown in Figure 1.

Figure 4 shows the plates on the lugs when half the plates in one series are turned at 180 to the plates in the other series.

I represents a plate and 2 a series of lugs cut 20 and punched therefrom. These lugs,are cut byr a die` in the ordinary way. l

When a plate I' (Fig. 3) has its lugs 2', 2 cut by the same die. if the plate I was placed above the plate I', the lugs 2 being smaller at their outer 25 ample in plate I would be in the position shown 30 in Figure 1, the corresponding notch 5' (Figure 3) would be in the position shown therein. Simultaneously with the punching of the lugs 2 and 2', the plates I and I' are provided with openings 4 and 4'. Now when the plates are put on the tubes 35 G, by reason of the openings 4 andl 4' as shown ln Figures 2 and 4, the lugs 2between the plates would bear on a solid part of the plate and not coincide with the holes 3 in the plates. The

notches 5, 5, conveniently guide the assembler 40 in placing the plates one over the other since the cut out notches 5, 5', would be arranged as shown in Figure 4 and when so arranged the smaller end of each lug would contact with the solid portion of the plate. prevent any rotation of the plates around the tubes and with the smaller ends of the lugs-bearing against the solid portion of the plates when the plates and lugs are assembledas shown in the drawing, my radiator has the maximum 50 strength and the maximum radiating qualities.

It will be observed also that when the plates are assembled on the tube 8, it is desirable that the holes 3 in theplates be not in alignment.

The hole in one plate out of line with the The tubes 6, furthermore, would 45 hole in the next plate will cause a tortuous line of circulation through the plates which, of course, is advantageous.

By punching out the lugs in both series of plates by the same die and then displacing the lugs in one plate with respect to those of the other by turning one plate through the holes and lugs are displaced relatively to each other and produce a superior arrangement. This construction results in having the bottom of the lug Where it joins the plate wider than the outermost end of the lug. This aids the flow of heat as compared with the type of lug, where' the small end of the lug is attached to the plate and, furthermore, puts a maximum section of the lug at a point of maximum strain when expanding the tube to make a tight iit in an opening 4 and by having each lug abutting a solid part of a iin when the entire construction is coated with metal, the metal will form a llet on each side of every lug where it touches an adjoining n plate. This llet increases the radiating surface as compared to the construction where a lug straddles a hole in the plate.

This application is a division of my application Serial No. 670,338, filed May 10, 1933 and patented December l1, 1934, No. 1,983,549.

Having now described my invention and the manner in which the plates are punched, and the lugs displaced by turning the plates through 180 when the plates are placed on a plurality of tubes, what I claim as new is:-

1. The method of making radiatorplates and assembling the radiator plates on tubes which comprises punching a plurality of plates by a single die to provide tube-engaging openings and to strike out lugs to leave holes, the lugs and corresponding holes in half of a plate being unsymmetrically arranged with those in the other half, turning alternate plates through 180 and assembling them in superposed relation on tubes, said tubes passing through the tube engaging openings, whereby the lugs on one plate will abut and be covered by the solid portion of the adjacent plate.

2. The method of making radiator plates and assembling the radiator plates on tubes, which comprises punching a plurality of plates to provide tube-engaging openings and to strike out lugs to leave holes, each lug being broader where it joins the plate than at its outer end, the lugs in corresponding holes in half of each of the plates being unsymmetrically arranged with those in the other half of each plate, turning alternate plates through 180 and assembling them in superposed relation on a plurality of tubes, said tubes passing through the tube engaging openings, whereby the lugs on one plate will abut and be covered by the solid portion of the adjacent plate.

3. The method of making radiator plates and assembling the radiator plates on tubes, which comprises simultaneously punching a plurality of plates to provide tube-engaging openings and to strike out the lugs to leave holes, the lugs in corresponding holes being unsymmetrically located on opposite halves of each of said plates, turning alternate plates through 180 and assembling the plates in superposed relation on a tube, said tube passing through the tube engaging openings, the lugs on one plate abutting the uncut solid portion of the adjacent plate.

HERMANN J. KRACKOWIZER. 

